The present invention relates to data acquisition systems and, in particular, to systems for processing radar return signals derived from particular transient events, such as lightning discharges.
Although the apparatus is primarily intended for the detection and analysis of transient echoes from lightning strokes other applications are recognized. For example, with some minor modifications the apparatus can be adapted for the detection and analysis of related transient events such as explosions, ballistics, etc. However, as will become apparent, a fundamental requirement for effective operation is that the echo or return signal from the target of interest must be initially greater than other return signals from the radar beam. Thus, generally considered, the present invention primarily contemplates applications involving particular, pre-selected echoes having the discriminatory strength characteristics which have just been noted.
Basically, there are two other methods of recording the amplitude and range of radar echoes produced by a transient event. Both, however, involve recording the entire video return signal from the radar receiver over the full length of time during which the transient event of interest might occur. The recorded data then must be subsequently reviewed by going back over the entire record to locate the transient events of interest. Such methods usually employ either magnetic tape, or oscilloscope and streak cameras and, for various reasons, they are quite impractical for high time resolution signals whose time of occurrence is not known precisely in advance. Lightning echoes, of course, are a prime example of such signals. The principle difficulty with these prior systems is that they do not allow an actual data reduction to take place prior to recording and in real time. Further, the required recording speeds for the recorders used are considerably greater and their ability to operate over extended periods of time is limited.